Tomatoes may reduce risk of stroke

9th October 2012

A diet rich in tomatoes may reduce the risk of having a stroke, according to researchers in Finland.

In a study involving more than 1,000 older men, researchers found those who had fairly high levels of the antioxidant lycopene in their blood stood a lower chance of suffering a stroke, over the 12-year period they were studied.

Lycopene is a reddish chemical that arises naturally in tomatoes, watermelon, red peppers and papaya. Most people are likely to encounter it in tomatoes, or in tomato purees and pastes.

Writing in the journal Neurology, researchers led by Jouni Karppi, of the University of Eastern Finland, in Kuopio, said the results are not conclusive proof that eating more tomatoes or products like ketchup will cut anyone's risk of stroke.

But they said a link is plausible, because lycopene is a potent antioxidant that helps to protect cells from damage that can eventually result in disease.

There is previous evidence to suggest that lycopene helps fight inflammation, which has been linked to a number of chronic diseases, and may do a better job than some other antioxidants.

In the study, which was funded by the Lapland Central Hospital, Karppi and his team followed a group of 1,031 men between the ages of 46 and 65 over a 12-year period, measuring their blood levels of lycopene, alpha- and beta-carotene, and vitamins A and E.

Out of the 25% with the lowest lycopene levels in the group, 25 suffered strokes during the course of the study, compared with just 11 among the 25% of study participants with the highest levels of lycopene.

They found that, even when other major risk factors like smoking, high blood pressure and diabetes had been taken into account, the high-lycopene group still had a 55% lower risk of stroke that the low-lycopene group.

There was no correlation between the presence of the other nutrients in the bloodstream and stroke risk.

According to Larry Goldstein, director of the Duke Stroke Center and a professor at Duke University Medical Center in Durham, North Carolina, who was not involved in the study, studies of this kind have significant limitations.

Laboratory research of this kind did not take into account the overall dietary habits of the men who participated, which could have some bearing on their overall risk of stroke, he said.

Goldstein warned that researchers and the general public are prone to putting too much faith in a single nutrient, and that a varied and healthy diet was still the key to good health.

Karppi also said the findings still strongly support current nutritional advice to get plenty of fruits and vegetables as part of a healthy diet.

Vitamin E and beta-carotene have previously been touted by researchers as a possible preventive intervention for heart disease.

But clinical trials of supplements later showed that vitamin E had no effect on heart disease risk, while beta-carotene supplements might even increase it.

Goldstein said the best way to eat for heart health was the "DASH" diet, which involves cutting salt and adding fibre-rich grains, nuts and legumes, along with low-fat dairy products.

Goldstein said tomatoes could form a part of people's "five-a-day," which is also recommended with the DASH eating plan.